Control system for railway traffic controlling devices



0. S. FIELD Sept. 29, 1936.

CONTROL SYSTEM FOR RAILWAY TRAFFIC CONTROLLING DEVICES Filed Feb. 25, 1.932

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Patented Sept. 29, 1936 UNITED ST AYES CONTROL SYSTEM FOR RAILWAY TRAFFIC CONTROLLING DEVICES Oscar S. Field, Rochester, N. Y., assignor to General Railway Signal Company, Rochester, N. Y.

Application February 25, 1932, Serial No. 595,131

13 Claims.

The present invention relates to control systems for railway traffic controlling devices and more particularly to a means for controlling a multiple aspect color light 'signaland for accurately indicating the aspect displayed by such signal at a central control point such as an interlocking tower.

In controlling railwaytrafiic control devices from a central point such as in an interlocking system" it is found economical and desirable to operate suchtraffic controlling devices from an alternating current source at places where a reliable supply of such current is available. In such control systems it is also essential to have an accurate indication that the-signal is actually displaying an aspect which corresponds to the'position of the control lever in as much as train operation may be endangered by the movement of an associated traffic control device, such as a switch 2 or derail, at times when the signal is not displaying a restricted indication.

In view of the above and other considerations it is proposed in accordance with the present invention to provide a signal control circuit which is operable from an alternating current source and by which an accurate indication may be received not .only'of the character of the displayed aspect but also of the actual display of such signal aspect.

3 Other objects, purposes and characteristic features of the invention will appear as the description thereof progresses, during which references will be made to the accompanying single figure of drawing which diagrammatically shows a circuit for controlling a multiple aspect color light signal in accordance with this invention.

Inthis drawing a signal control lever L is shown as being operable'to two distinct positions Rand Y and has associated therewith an indicating relay IR and an indicating lamp I has been diagrammatically shown as typical of a function which this relay may perform. A signal mechanism has been diagrammatically shown in the dotted rectangle S and may be of the type shown in my prior application Ser. No. 470,056 filed June The signal mechanism here illustrated is of the mil-.thevane. l to a positionin which the"yel1ow spectacle y aligns with the signallampwsL. A contact 3 is operated by the movement of this vane 4 through an arm 4 to makeup either back-- point 5 or front point 6 according to'the position of the vane I. y

In as much as these signal mechanismsSare' designed for direct currentoperationgit is founddesirable to insert a rectifying -:unit 1 in series I with the operating winding Wto obtain satisfactory operation of the vane 'I but it is obviousthat with mechanisms designed for alternating -cur rent operation it may be omitted. A source of alternating current supply is indicated as being received from a transformer T and a wire C=leading therefrom is the common'wirefor-the signal S and may be extended throughout the'systentas a common wire to other mechanisms whichare-- similarly controlled. The signal lamp 'SLisenergized from a secondarywinding of a lighting transformer LT which has: a primary winding in series with the circuit for indicating a restrictive signal indication as will be: later described.

The signal lever L isillustrated as assuming a position R in which it conditions thesignal mechanism S to display a red, the most restrictive, indication in as much as the winding .Wisnot energized to attract the vane l and itassumes its biased center position in which the-red spectacle 1' aligns with the signal lamp SL1 Ariindication of this display of a red indication is obtained by the energization of the indicating relay IR as follows:beginning at the secondary winding the transformer T wire 9, lever contact 10" in its left hand position, wire it through'the winding of relay IR, wire l2, signal contact 3 made at its back point' 5, "wire l3, throughthe primary winding of transformer LT, wires I4 and E5 to the common wire C and back'to the' other side of the secondary of the transformer-I. The" indication obtainablefrom the indicating'relay' IR may be employed in "any manner to suitthe requirements of the particular system such as the locking of conflicting control levers, butherein has been shown asenergizing an indicatin-g'lamp I over an obvious circuit made at front contact- 45 E6 of the relay IR.

Now considering that itisdesiredto operate the signal S to display a less restrictive indica=- tion thesignalleverL is operated'to a-positio'n Y and a circuitis then made-up to-energ-ize=th-- winding W as follows:begin'ning at the -sec=- ondary of the transformer T, 'wir'e-Qfllever con--- tact l0 in its right hand position, wire lilyconta ct I I9 of relay IR which is now' de energized in asmuch as its circuit is broken-by contact. 1 0: mov 551.

ing to its right hand position thereby completing the circuit from this contact I9 to wires 20 and 2 I, through the rectifier I and the operating winding W, wire I5 to the common wire C and back to the transformer T.

The energization of the winding W moves the vane I as previously stated, to a position in which the spectacle y aligns with the signal lamp SL and the contact 3 is of course operated to a left hand position by this movement of the vane I. A circuit for energizing the lighting transformer LT is again completed which is in parallel with the operating winding W and may be traced from the energized wire 20 through wire 22, a resistor 23 wire 24 through back point 6 and contact 3, wire l3 primary of the lighting transformer LT, wires I4 and I5 to the common wire C. This energizes the signal lamp SL from the secondary of this lighting transformer LT the same as in displaying the red indication but in as much as the yellow spectacle y is now in a position aligning with the signal lamp SL the yellow indication is displayed and the display of this less restrictive signal aspect is controlled, and hence is indicated at the control point, by the de-energization of the indicating relay IR provided, of course, that the described circuits are intact. The resistor 23 is provided in the signal lighting circuit in this case to compensate for the resistance of the windings of relay IR which is inserted in this circuit during the display of a red indication. The lighting circuit is then of the same resistance in either case which maintains equal intensity of signal indications.

It is now obvious that an accurate check on the display of the most restrictive or the red indication of the signal mechanism S is obtained by providing the contact 3 in series therewith which directly checks the character of the aspect through the position of the vane I. A further check is obtained on the presence of signal light in as much as a condition in which this signal lamp does not draw current from the secondary of the lighting transformer LT, such as may be brought about by a burned out filament, sunficiently increases the impedance of the primary to reduce the current in the indicating relay IR to a degree effecting the opening of its contact I6 and thereby preventing a false indication at the control point.

The present invention also contemplates a means for preventing a false indication due to an out-of-correspondence condition between the signal mechanism S and the control lever L which may be brought about by a cross or short circuit between the control wires I2 and 2!]. For example, a circuit energizing the winding W of the signal mechanism to give a yellow indication when the control lever L is in its red or R position may be completed due to a cross as follows:-- from transformer T, wire 9, lever contact ID in its left hand position, wire II, windings of relay IR, wire I2 through a short circuit or cross to wire 20, wire 2|, rectifier l, operating winding W, wire I5, common wire C back to transformer T.

It will be noted in the above circuit that the winding of the relay IR is in series with the operating coil W of the signal mechanism and consequently if this coil W is arranged to present sufiiciently greater impedance to this circuit than is offered-by the lighting transformer LT under normal conditions, the current value of this cross circuit will be reduced to a point ineffective to cause opening of contacts 35 and consequently the correct indication of the signal aspect will remain at the control point.

A system for controlling a color light signal has thus been provided which is adaptable to use in an interlocking plant where it is found desirable to employ alternating current for operation and which provides an indicating means which is sufficiently reliable to meet the requirements of the interlocking between other conflicting control levers.

The above rather specific description of one form of the present invention is given solely by the way of example and not intended in any manner whatsoever in a limiting sense. It is also to be understood that various modifications, adaptations and alterations will be supplied to meet the requirements of practice without in any manner departing from the spirit or scope of the present invention except as limited by the appended claims.

Having thus described my invention, what I claim is:

1. In a manually controlled signal system for railroads, a color light signal mechanism biased to display a most restricted indication, an electric light source for the signal mechanism, a control lever for said signal mechanism, energizing means including an alternating current rectifying unit for operating said signal mechanism to display a less restricted indication in accordance with the position of said control lever, and means for energizing a relay when said signal mechanism displays a most restricted indication in correspondence with said control lever, and only when current flows in the light source of said signal mechanism.

2. In a manually controlled signal system for railroads, a signal mechanism biased to display a most restricted indication, a control lever for said signal mechanism, a lever contact, energizing means including an alternating current rectifying unit for operating said signal mechanism to display a less restricted indication in accordance with the position of said control lever, and a circuit, including the lever contact, for energizing a relay effective when said signal mechanism displays a most restricted indication in correspondence with said control lever.

3. In a signal control system, a multiple aspect signal mechanism normally displaying a danger signal, an indicating relay, a control lever, a lever contact, circuit means controlled by said relay and by said control lever for operating said signal mechanism to display a less restricted indication, contact means operated by said signal mechanism in accordance with the character of the signal, and a circuit, including the lever contact and signal mechanism contact means, for energizing said relay when said signal mechanism contact is in correspondence with said control lever contact.

4. In a signal control system, a signal lamp, a transformer having a secondary winding supplying current to said signal lamp, a manually controlled signal mechanism operable to variously cooperate with the signal lamp to thereby display a plurality of signal aspects, an indicating relay, and an energizing circuit for said relay including a primary winding of said transformer arranged to open said indicating relay contacts when the impedance of the primary winding is increased by the cessation of flow of current in the secondary Winding.

5. In a signal control system, a single signal lamp, 2. signal mechanism arranged to determine the color of indication displayed by said lamp, means biasing said signal mechanism to display a red indication, power operated means for moving said signal mechanism to a position for displaying a yellow indication, a control lever, a signal indicating relay, a source of alternating current energy, a circuit energizing said signal mechanism operating means from said source of energy including a back contact on said indicating relay and controlled by said control lever, an energizing circuit for said signal lamp including contacts made when said signal mechanism is in said yellow signal position and an energizing circuit for said indicating relay in series with a lighting means for said signal lamp including contacts made by said signal mechanism in its biased position and contact means operated by said control lever.

6. Signal control circuits comprising a movable signal mechanism and a light source, manually operable means for controlling the aspect displayed by said signal mechanism, and signal indicating means arranged to check the correspondence between the position of said manually operable means and the aspect displayed by said signal mechanism and the energization of the light source.

7. In a signal control system, a multiple aspect signal mechanism including a light source and normally displaying a danger signal, an indicating relay, a control lever, circuit means controlled by saidrelay and by said control lever for operating said signal mechanism to display a less restricted indication, contact means operated by said signal mechanism in accordance with the character of the signal, and a circuit energizing said relay when said signal mechanism is positioned to display a danger indication in correspondence with said control lever and only when the light source is intact.

8. In a signal control system, in combination, a light signal having a light source and a cooperating spectacle, a spectacle contact movable by the spectacle, a remote control lever for the signal, an indication relay controlled by the lever and the spectacle contact and energized when the lever and spectacle contact are in correspondence with the signal giving its most restrictive indication.

9. In a signal control system, in combination, a light signal having a light source and a cooperating spectacle, an operating winding for the spectacle, an energizing winding for the light source, a spectacle contact movable by the spectacle, a remote control lever, an indication relay controlled by the lever and the spectacle contact and energized when the lever and spectacle contact are in correspondence with the signal giving it most restrictive indication, the energizing circuit for the indication relay including said energizing winding, the energizing circuit for said operating winding including a back point of the indication relay and a lever contact when the lever is in a position corresponding to a less restrictive signal indication.

10. In a signal control system, in combination, a light signal having a light source and a cooperating spectacle, an operating winding for the spectacle energizable over a control wire, an energizing winding for the light source, a spectacle contact movable by the spectacle, a remote control lever, an indication relay controlled by the lever and the spectacle contact over an indication wire and energized when the lever and spectacle contact are in correspondence with the signal giving it most restrictive indication, the energizing circuit for the indication relay including said energizing winding, the energizing circuit for said operating winding including a back point of the indication relay and a lever contact when the lever is in a position corresponding to a less restrictive signal indication, the impedance of the said operating winding being greater than that of the said energizing winding, whereby a cross between the control and indication Wires, when the signal is giving its most restrictive indication, energizes the operating winding in series with the indicating relay to an extent insufficient to operate the spectacle.

11. In a signal control system, in combination, a light signal having a light source and a cooperating spectacle, an operating winding for the spectacle energizable over a control wire, an energizing winding for the light source, a spectacle contact movable by the spectacle, a remote control lever, an indication relay controlled by the lever and the spectacle contact over an indication wire and energized when the lever and spectacle contact are in correspondence with the signal giving it most restrictive indication, the energizing circuit for the indication relay including said energizing winding, the energizing circuit for said operating winding including a back point of the indication relay and a lever contact when the lever is in a position corresponding to a less restrictive signal indication, the impedance of the said operating winding be- 'ing greater than that of the said energizing winding, whereby a cross between the control and indication wires, when the signal is giving its most restrictive indication, energizes the operating winding in series with the indicating relay to an extent insufficient to operate the spectacle having an energizing circuit including a contact of the lever in its less restrictive position, a back point of the indication relay, and the spectacle contact in position corresponding to the lever position.

12. In a signal control system, in combination, a light signal having a light source and a cooperating spectacle positionable to give different indications, a spectacle contact movable by the spectacle, a remote control lever for the signal for controlling the spectacle, an indication relay controlled by the lever and the spectacle contact and energized only when the lever and spectacle contact are in correspondence with the signal giving its most restrictive indication.

13. In a signal control system, a multiple aspect signal mechanism normally displaying a danger signal, in indicating relay, a control lever, a lever contact, circuit means controlled by said relay and by said control lever for operating said signal mechanism to display a less restricted indication, contact means operated by said signal mechanism in accordance with the character of the signal, and a circuit, including the lever contact and signal mechanism contact for energizing. said relay when said signal mechanism contact is in correspondence with said control lever contact and then only when the mechanism is positioned to display a danger indication.

OSCAR S. FIELD. 

